Environment – NZ’s Angry Birds game

Pukeko are one of the most fascinating of our native fauna. Often unappreciated, these intelligent and charismatic birds are very easy to watch. Next time you get a chance, take some time to watch what they are up to. 

The pukeko is an NZ endemic subspecies of purple swamphen. They are highly gregarious creatures that stay together in stable social groups. Often within a group there are multiple breeding individuals, as well as numerous (typically youngish) non-breeders. Within any nest there can be eggs that have been fathered by multiple males and laid by multiple females. The young are then raised by all the members of the group and groups will defend their territories fiercely.

This is known as a “communal” mating system – but all is not always harmony within a group. There are countless squabbles and aggressive interactions going on. Although this aggression rarely escalates into outright violence, pukekos frequently chase, peck and threaten each other. Similar to many human families, bickering within the family group is common but this does not mean the group as a whole is not a cohesive and loyal entity. 

Pukekos have a special visual signal that helps facilitate the constant bickering: their red facial shields. At Massey University, my colleagues and I have done a fair bit of research on the signalling value of this conspicuous ornament. 

Our studies have shown that pukeko shields are what is known as “badges of status” they are a signal to other pukekos about how dominant they are. The bigger the shield – the more dominant they are in aggressive interactions. 

It is basically like a karate belt. Assuming you are not an actual black belt, there is nothing stopping you going to the shop and buying yourself one and walking into a karate competition. But why would you do that? You would just be inviting competition from people who will soundly kick your butt! 

In the pukeko world, any individual that falsely advertises they are more dominant with a bigger shield will likely get challenged regularly. During these tests, any detection of weakness (that is, false advertising) results in rapid escalation and possible injury. So, it is in the interests of each pukeko to advertises its position in the pecking order honestly – the ones that have the skills and experience to truly dominate are the ones with the biggest shields. They are the only ones who can handle any challenges associated with showing off.